Every death on every road in Great Britain 1999-2010; From 1999-2010 36,371 people. A total of 36,371 people were killed on Britain's roads between 19. June 19, 1999 Web posted at: 11:21 p.m. EDT (0321 GMT) (CNN) -- Horror author Stephen King was seriously injured when he was struck by a minivan while walking in. Michael Schumacher crash onboard Ferrari, en el Gran Premio de Canada de 1999. Accidente en la curva de los campeones. Tokaimura Criticality Accident 1999 (Updated October 2013) In 1999 three workers received high doses of radiation in a small Japanese plant preparing fuel for an. Tokaimura Criticality Accident - World Nuclear Association(Updated October 2. In 1. 99. 9 three workers received high doses of radiation in a small Japanese plant preparing fuel for an experimental reactor. The accident was caused by bringing together too much uranium enriched to a relatively high level, causing a 'criticality' (a limited uncontrolled nuclear chain reaction), which continued intermittently for 2. 1999 Statistics See Also 2005 Fatal Stats >> Car Accidents in the United States: There were an estimated 6,289,000 police-reported crashes in 1999- based on data. A total of 1. 19 people received a radiation dose over 1 m. Sv from the accident, but only the three operators' doses were above permissible limits. Two of the doses proved fatal. The cause of the accident was . A secondary focus is then the high- level wastes from the reactor, which comprise all the potentially hazardous materials from the reactor core. Other parts of the nuclear fuel cycle have much less potential for widespread harm to people or the environment. They are correspondingly less regulated in some countries, such as Japan. The Tokaimura plant. The 1. 99. 9 Tokai- mura accident was in a very small fuel preparation plant operated by Japan Nuclear Fuel Conversion Co. It was not part of the electricity production fuel cycle, nor was it a routine manufacturing operation where operators might be assumed to know their jobs reasonably well. The particular JCO plant at Tokai was commissioned in 1. U- 2. 35, a much higher than for ordinary power reactors. The plant supplied various specialised research and experimental reactors. It uses a wet process. The approved nuclear fuel preparation procedure involved dissolving uranium oxide (U3. O8) powder in nitric acid in a dissolution tank, then its transfer as pure uranyl nitrate solution to a storage column for mixing, followed by transfer to a precipitation tank. This tank is surrounded by a water cooling jacket to remove excess heat generated by the exothermic chemical reaction. The prevention of criticality was based upon the general licensing requirements for mass and volume limitation, as well as upon the design of the process. A key part of the design was the storage column with a criticality- safe geometry and allowing careful control of the amount of material transferred to the precipitation tank. However, the company's work procedure was modified three years earlier, without permission from the regulatory authorities, to allow uranium oxide to be dissolved in stainless steel buckets rather than the dissolution tank. It was then modified further by the operators to speed things up by tipping the solution directly into the precipitation tank. The mixing designed to occur in the storage column was instead undertaken by mechanical stirring in the precipitation tank, thus bypassing the criticality controls. Also there was no proper control of the amount tipped into the hundred- litre precipitation tank, and its shape (4. The accident. On 3. September three workers were preparing a small batch of fuel for the JOYO experimental fast breeder reactor, using uranium enriched to 1. U- 2. 35. It was JCO's first batch of fuel for that reactor in three years, and no proper qualification and training requirements had been established to prepare those workers for the job. They had previously used this procedure many times with much lower- enriched uranium - less than 5%, and had no understanding of the criticality implications of 1. At around 1. 0: 3. U, a critical mass was reached. At the point of criticality, the nuclear fission chain reaction became self- sustaining and began to emit intense gamma and neutron radiation, triggering alarms. There was no explosion, though fission products were progressively released inside the building. Tour Accident 13 Dead '12 dead in tourist boat accident at Hot Springs' Northwest Arkansas Times.The significance of it being a wet process was that the water in the solution provided neutron moderation, expediting the reaction. It appears that as the solution boiled vigorously, voids formed and criticality ceased, but as it cooled and voids disappeared, the reaction resumed. The reaction was stopped when cooling water surrounding the precipitation tank was drained away, since this water provided a neutron reflector. Boric acid solution (neutron absorber) was finally added to the tank to ensure that the contents remained subcritical. These operations exposed 2. The next task was to install shielding to protect people outside the building from gamma radiation from the fission products in the tank. Neutron radiation had ceased. The radiation (neutron and gamma) emanated almost entirely from the tank, not from any dispersed materials. Buildings housing nuclear processing facilities such as this are normally maintained at a lower pressure than atmosphere so that air leakage is inward, and any contamination is removed by air filters connected to an exhaust stack. In this case particulate radionuclides generated within the conversion building were collected by the high- efficiency particulate air filters, though noble gases passed through the filters. A smoke test on 5 October confirmed that the negative pressure had been maintained (ie the structural integrity of the building was satisfactory) and that the ventilation system was working. However, owing to the detection of low levels of iodine- 1. Five hours after the start of the criticality, evacuation commenced of some 1. They were allowed home two days later after sandbags and other shielding ensured no hazard from residual gamma radiation. Twelve hours after the start of the incident residents within 1. Plan of site from STA, data quoted below from monitoring point A, that from B is slightly lower. The effects, and analysis. The accident was classified by the Japanese authorities as Level 4 on the International Atomic Energy Agency (IAEA) International Nuclear Event Scale (INES)*, indicating an event without significant off- site risk. It was essentially an 'irradiation' accident, not a 'contamination' accident, as it did not result in any significant release of radioactive materials. Japan’s Science & Technology Agency estimated that 2. MJ (the energy in 2. The three workers concerned were hospitalised, two in a critical condition. One died 1. 2 weeks later, another 7 months later. The three had apparently received full- body radiation doses of 1. Sv is normally a fatal dose), mainly from neutrons. Another 2. 4 JCO workers received up to 4. Sv. Doses for 4. 36 people were evaluated, 1. None exceeded 5. 0 m. Sv (the maximum allowable annual dose), though 5. Sv and a further 2. Seven workers immediately outside the plant received doses estimated at 6 - 1. Sv (combined neutron and gamma effects). For members of the public, estimates are that one received 2. Sv, four 1. 0- 1. Sv, and 1. 5 received 5- 1. Sv. The peak radiation level 9. Sv/hr of gamma radiation, but no neutron levels were measured at that stage. The gamma reading then dropped to about half that level after nine hours at which stage 4. Sv/hr of neutron radiation was measured there, falling to about 3 m. Sv/hr after a further two hours, and then both readings falling to zero (or background for gamma) at 2. Neutron dose rates within one kilometre are assumed to be up to ten times the measured gamma rates. Based on activation products in coins from houses near the plant boundary and about 1. Sv of neutron radiation would have been received by any occupants over the full period of the criticality. However, the evacuation of everyone within 3. The final report on the accident said that the maximum measured dose to the general public (including local residents) was 1. Sv, and the maximum estimated dose 2. Sv. While 1. 60 TBq of noble gases and 2 TBq of gaseous iodine were apparently released, little escaped from the building itself. After the criticality had been terminated and shielding was emplaced, radiation levels beyond the JCO site returned to normal. Only trace levels of radionuclides were detected in the area soon after the accident, and these were short- lived ones. Products from the area would have been as normal, and entirely safe throughout. Radiation levels measured by the IAEA team in residential areas in mid October were at the normal background levels. Measurement of I- 1. According to the IAEA, the accident . The company conceded that it violated both normal safety standards and legal requirements, and criminal charges were laid. The fact that the plant is a boutique operation outside the mainstream nuclear fuel cycle evidently reduced the level of scrutiny it attracted. The state regulator had visited the plant only twice per year, and never when it was operating. Japan's atomic energy insurance pool said would make a payment to JCO in respect to the accident, its first such payment ever. However, this would be limited to one billion yen, with further liability (the total estimated at 1. A$ 2. 00 million), being met by JCO or its parent company. The plant's operating licence was revoked early in 2. Mainstream fuel fabrication plants in Japan are fully automated, engineered to ensure that criticality does not occur, equipped with neutron monitoring systems and fully prepared for any possible criticality accident. Most plants use a dry process in any case, which is intrinsically safer. No major civil reactor uses uranium enriched beyond 5% U- 2. Previous criticality accidents. While this was Japan's first such accident, similar criticality incidents have occurred, especially in US and Russian military plants and laboratories. All but two of these were prior to the early 1. Three (in 1. 95. 8 and 1. The last of these was the single previous criticality accident at a commercial fuel plant, in USA, resulting in one death. Of all the previous accidents, 3. Another 2. 2 occurred in fuel cycle facilities, all but one military- related, and resulting in seven deaths. The energy released in each of these accidents ranged from about 0. MJ to 3 GJ*. The energy released in the similar US accident was about 3 MJ, though due to the prolonged criticality here, some 8. MJ was released, equivalent to the combustion of just over two litres of petrol/gasoline.* on basis of IPSN report quoting fissions ranging from 1.
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